Whenever we install a new kernel or a driver, etc GRUB automatically generates a configuration file "grub.cfg"
It makes a lot of output and can repeat itself. We can simplify it greatly. There is an example of a modified file
for a Multi OS booting list included in the package. Screenshot 1 shows a cleaned up menu. Screenshot 2 shows a machine generated list
Screenshot 3 a modified file showing a background image.

This app will reset grub to the grub menu file modified by the user
Unless one wants to run the previous kernel this modified file will never have to be changed
The reset script creates a backup with a time-stamp of the new machine generated grub.cfg file
Then it overwrites grub.cfg with our modified file grub.cfg.mod
Then it shows a simulation of the boot menu as proof of the reset

Prerequisites are that 'zenity' and 'grub-emu' are installed and
that the user saves the original file: /boot/grub/grub.cfg to /boot/grub/grub.cfg.orig
that the user modifies the original file and saves it to: /boot/grub/grub.cfg.mod
There is instructions on the modification included in the package

Installing the app is just a matter of copying via a terminal:
For Ubuntu 18.04 and later do this first: sudo mkdir /usr/share/images
For earlier Ubuntus, including 4 CLIX 9 or Ubuntu-16.04, which already have this folder,
we can start at this step > Extract downloaded file: Reset-Grub.tar.gz
Open a terminal inside newly extracted folder 'Reset-Grub' and type one at a time:
sudo cp -R desktop-base /usr/share/images/
sudo cp grub-logo.png /usr/share/icons/
sudo cp Reset-Grub.desktop /usr/share/applications/
sudo cp reset-grub /usr/bin/
sudo chmod a+x /usr/bin/reset-grub

The app: Reset-Grub will appear in Menu > System Tools > Administration